Locking mechanism for electrical-lamp sockets.



W. BROAD.

LOOKiNG MECHANISM FOR ELECTRIC LAMP SOCKETS.

APPLICATION FILED MAR. 26, 1912.

1,053,354. Patented Feb. 18, 1913.

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LOCKING MECHANISM FOR ELECTRIC-.-LAMP SOCKETS.

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Specification of Letters Patent.

Patented Feb. 18,1913.

Application filed March 26, 1912. Serial No. 886,401.

To all whom it may concern:

Be it known that 1, WILLIAM BROAD, a'

citizen of the United States, residing at Beaver Falls, in the countyof'Beaver and State of Pennsylvania, have invented a certain new anduseful Improvement in Looking Mechanism for Electric-Lamp Sockets, or"which the following is a-specification.

The primary object of my invention is a concealed locking mechanism,coiiperating with the well known'and' commonly used socket for retainingan electric light bulb or lamp of the incandescent type, whereby thelamp or bulb is held and secured against removal from the socket untilsuch a time as the life of the lamp is exhausted or burned out. Thislocking device insures the retention of the lamp until its usefulness isexpended, preventing theft thereof, and can only be removed from thesocket by breaking or destroying the glass bulb.

I do not set up 'any claim for novelty or invention in the socketitself, as my idea is applicable to any of the numerous sockets now incommon usage, nor .do I desire to limit myself to any particular styleor configuration of socket, but what I do claim as my invention is thebasic idea of arranging a simple, comparatively inexpensive, andpositive concealed locking mechanism. in conjunction with any suitableform of socket.

I am aware that inventions for a somewhat similar purpose and intentionhave been patented heretofore, some involving keys, while others adoptan additional fixture to enter the socket, thereby adding to andextending-the length of the ordinary socket fixture.

I do not alter the size'or shape. of the socket, but arrange my lockingmechanism interior or the socket, concealed from view, andinaccessiblefor being reached by any tool or instrument, or for beingtampered with in any manner whatever.

My invention therefore involves the constructive features, andcombination of old and new elements, hereinafter specifically describedin detail, and shown in the accompanying drawing.

Referring then to said drawing, which illustrates one embodiment of myinvention: lti ure 1 is anexterior view in elevaworkin appearance of theordinary well known lamp socket with bulb attached; Fig. 2 is a verticalsection of my improved lock socket showing the relative positions of thenew elements involved in my invention; F g. 3 is an enlarged tragmentalView, partly in section, of the'assembled features incorporated in thisinvention; Fig. 4is a I plan view of a non-metallic disk used inconjunction with the remaining elements; Fig. 5-shows a plan view of afixed member involving a notch-or aperture, and carrying a ratchetspring element; Fig. 6 is an inverted view in perspective of the fixedmember in its blank formation; Fig. 7 shows the blank formation of arotatable element to receive and retain the screw base of the lamp; andFig. 8 is an edge view of the member shown in Fig. 5.

Throughout the respective views the numeral 1 designates the crown orcap portion of a lamp socket, which is of ordinary construction, andused for a purpose well known in the art, the lower extremity of whichpart carries and supports the removable shell or casing 2, which isalso'oii' ordinary construction, and houses the interiorly positionedworking parts, including the porcelain or non-metallic head piece 3.This said head 3 is of ordinary construction and usage, also well knownin the art, involving suitably positioned recesses 4 in the upperportion thereof for receiving the inner ends of thumb screws 5, whichare here shown in the formation of knurled or. milled ball heads, forconvenience in removing or tight ening up purposes, having screw shankswhich pass through the two members 1 and 2, entering said recesses 4;thereby securing all three arts in removable position. The inner end sout said screw 5 are preferably flattened slightly, after insertionthrough the said members 1 and 2, in order to prevent being entirelybacked out, when it becomes necessary to drop the casing 2 in order toexpose the interiorly positioned parts.

Canned by the lower extremity of the non-metallic member 3, ,and closelyengaging the same as shown preferably by means of the bolts 6, shown'inFi 2, 1s the fixed mem er 7 scenin'Fig. 6, which involves an aperture 8formed in the flange portion 9,

and flared or hell mouthed apertures 10 to receive and counter-sink thescrewrheads of said bolts 6; a space of sufiicient area being allowedbetween said bolts to prevent arcing at this point, and carry out'a wellknown electrical construction in devices of this nature.

The rotatablesheath or screw sleeve member '11, which receives andretains the screw base of the lamp, shown in blank formation, Fig. 7, isprovided in its upper extremity with an aperturel2, and also carries thenon-metallic, preferably porcelain, disk 13, shown in detail Fig. 1.This said member 13 is preferably provided with "a rounded 01f edge, andis held in fixed position within the said member 11 by crimping orbeading the upper edge thereof over the said rounded periphery of thedisk 13; the aperture 12 registering with a notch 14 formed in saiddisk. This latter mentioned member is provided with apertures 15, topermit free insertion through the said disk of-securin'g bolts 6, andregister with the aperture 10,

also with a central aperture 16 to receive a metallic contact piece 17.A suitable spring element 18 seated between said member 17 and currentconductor 19 carried by the head 3, affords sufficient contact to carrycurrent in proportion with the capacity of the socket, and overcomes anylooseness or play of the respective parts.

When assembling my device the depending flange portion 9 of the fixedmember 7 is spun or otherwise turned to form a race or guide embracingthe beaded top of the rotatable sheath 11, whereby said member 11 willbe allowed free and unhampered movement within said fixed member 7, be

I adequately supported thereby, and bear the combined weight of the lampand sheath.

As will be seen by reference to the drawings the notch 14 formed in therotatable disk 13, is provided with a tapered surface and also astraight or vertical portion; for a purpose to be more fully explainedfarther on. A spring actuated dog or ratchet 20 is firmly secured at oneend-to the rounded ofl flange 9 exteriorly of the fixed member7, thefree end thereof adapted to engage in the notch 14. This .constructionpermits the free uninterrupted rotary movement of the sheath 11 andsecured disk 13 mono direction within the fixed housing 7 and thisrotary movement can be kept up indefinitely, as the ratchet 20 will ridethe I tapered part of the notch 14 at every revolution, but on a reversemovement of the said sheath the spring ratchet will catch against thestraight face of saidnotch 14 and arrest further rotation of saidsheath; It will thus be readily apparent that when a lamp, involving theordinary well known screw base, is inserted in the socket, entering .l esheath 11, said lamp may be turned to the limit of'its screw thread,andto revolve just as soon as the ratchet 20 engages against thestraight face of the notch 14, the result being that upon a stillfurther rotation of the lamp it will be turned more securely into saidsheath. I

After the lamp is once positioned in the socket, and secured by therevoluble sheath, no separation between these two elements is possiblewithout first breaking the glass bulb, unloosening the set screws 5, andpermitting the casing 2 being slipped down over the sheath and lampbase. When the concealed locking mechanismpis thus exposed to view it ispossible to ecfiect a speedy and easy separation of the lamp base fromthe sheath, in order to replace with a new one, by simply grasping saidsheath in one hand, or by a suitable gripping tool, and with the otherhand turn said lamp base out of its seat in the sheath. If theglass bulbshould be broken off close up to the said base, thereby reducing thegripping surface, a prepared tool of simple and inexpensiveconstruction", to be inserted therein and turn the said base while thesheath is being held firmly, can easily be provided for.

The added features of the rotatable sheath or screw sleeve, to receivethe lamp base, fixed race or housing to receive the said sheath, andmeans for permitting uninterrupted rotation of the combined sheath andlamp in one directi n, and for locking them against movement in theopposite direction, which combination of new elements forms the basicfeatures of my invention, when assembled as shown, in conjunction withany adequate form of lamp socket, Wlll not interfere or endanger therequisite essentials of proper insulation and good electrical contactnecessary to a' device of this nature;

The construction here shown renders my device applicable to beingutilized in any desired osition, or at any angle, and in conjunctionwith various forms and welghts of shades, without endangering theseparation of the parts or of short .circulting.

Various modifications and alterations in the detail form ,ofconstruction and assembling the several 'elements may be necessary asthe progress of experimentat on advances, therefore I do not l1m1tmyself to the exact formation or arrangement of the respective partsshown and herewlth described, reserving the right to make' suchalterations as may be deemed necessary,

without departing from the original spirit of the invention, and thatwill be within 1 ment. when turned in an opposite direction.

2. 'In a locking mechanism for" electric 1am sockets, a fixed memberpositioned at the ower extremity of the insulating head portion, andinteriorly of the casing, in

volving a circular grooved race or gu1de; a

memberto receive and retain the screw base of the lamp, involving aninsulating head portion rovided with one or more ratchet teeth, a aptedfor uninterrupted rotation within'the said race portion when turned inone direction; and a pawl, carried by the .fixed member and engaging inthe teeth formed in the rotatable member, for locking said latter memberagainst movement when turned in anopposite" direction.

3. In a lock socket for electric lamps, the combination with theporcelain head and removable outer casing, of a conoealed'lockingmechanism'involving a fixed member rigidly secured to the said head, inwhich is a circular grooved race or guide portion supplied with anaperture and carrying a spring actuated pawl to engage in said aperture,and a screw socket to receive the lamp base, involvin a beading providedwith one or more ratc et teeth, to seat in and be clenched by saidcircular race, and adapted for indefinite rotation in one direction, butlocked against rotation by said pawl engaging in the ratchet teeth whenturned in an opposite direction.

4. An electric lamp socket having a concealed locking mechanisminvolving a fixed member and a rotatable screw sleeve toreceive the baseof the lamp, a beading carried by the upper portion of said sleeve inwhich, is one or more ratchet teeth, a circular cular groove ing, and aspring actuated pawl carried by the race portion to enter said apertureengage in the teeth and hold said sleeve against rotation when turned inan opposite direction. I

5. In a lock socket for electric lamps the combination with theporcelain head, involving suitable contacts, and removable outer casing,of a locking mechanism normally concealed and protected by the saidcasing when the lamp is in position in the socket, and requiringbreakage of the lamp to lower .the said casing and expose the lockinmechanism, said mechanism involving a fixe member secured totheporcelain head and carrying a circular grooved race or guide portionin which is an aperture, a rotatable screw sleeve to receive the base ofthe lamp,

its upper portion carrying a heading supplied with one or more ratchetteeth, said member being heldfor indefinite rotation in one directionwithin the said race, and a pawl carried by the said race adapted toengage in the teeth and lock said sleeve against movement when turned inan opposite direction.

6. A new article of manufacture consist ing of a su porting memberhaving a circurace or guide, a second memlar groove ber held forrotation within the said guide, and means .for locking the saidsecond-member against movement when rotated in. one direction. Y

7. Anew article of manufacture consist ing of a supporting member havinga cirrace or ide involving'an aperture, a pawl carried y the saidmember, a second member held for rotation within the first member,involving a ratchet adapted to be engaged by the said pawl to lock saidsecond member against movement when turned in one direction. o

8. A new article of manufacture consistingof a supporting member havin ac'ircular groove aperture, a pawl carriedby the said member, .21.,second member involving a beadin in which is one or more ratchet teeth,held for uninterrupted rotation within the first member when turned'inone direction, but locked against movement by the said pawl and ratchetteeth when turned in an opposite direction.

In testimony whereof, I afiix my signature in the presence of twowitnesses.

WILLIAM- BROAD. Witnesses 'EowAnn G. JENNINGS,

EMMA F. SEA.

Copies of this patent may beobtained for five cents each, by addressingthe Commissioner of Iatents,

Washington, D. C.

